Sökning: "Diazotrophic"

Visar resultat 6 - 10 av 21 avhandlingar innehållade ordet Diazotrophic.

  1. 6. Filamentous cyanobacteria in the Baltic Sea - spatiotemporal patterns and nitrogen fixation

    Författare :Lisa Almesjö; Ragnar Elmgren; Norbert Wasmund; Stockholms universitet; []
    Nyckelord :Aphanizomenon sp.; Nodularia spumigena; Baltic Sea; image analysis; spatial variability; nitrogen fixation; vertical migration; marin ekologi; Marine Ecology;

    Sammanfattning : Summer blooms of filamentous, diazotrophic cyanobacteria are typical of the Baltic Sea Proper, and are dominated by Aphanizomenon sp. and the toxic Nodularia spumigena. Although occurring every summer, the blooms vary greatly in timing and spatial distribution, making monitoring difficult and imprecise. LÄS MER

  3. 7. Non-cyanobacterial nitrogen fixation insights in humic freshwater lakes and ponds

    Författare :Leyden Fernandez-Vidal; Stefan Bertilsson; Sari Peura; David Walsh; Uppsala universitet; []
    Nyckelord :humic lakes; thaw ponds; non-cyanobacterial diazotrophs; nitrogen fixation; nitrogenase;

    Sammanfattning : The biological basis of nitrogen fixation beyond the canonical role of Cyanobacteria is not well understood in freshwater ecosystems. To address this gap in knowledge, the main objective of this thesis is to study non-cyanobacterial nitrogen fixation in freshwater lakes and ponds. LÄS MER

  4. 8. External Growth Control of Baltic Sea Cyanobacteria

    Författare :Anna Zakrisson; Ulf Larsson; Jakob Walve; Elena Gorokhova; Sanna Suikkanen; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Baltic Sea; cyanobacteria; nitrogen fixation; heterocysts; Aphanizomenon; Nodularia; water treatment; Himmerfjärden; sewage; climate; Marine Ecology; marin ekologi;

    Sammanfattning : In the Himmerfjärden Bay a large excess of nitrogen over phosphorus in the discharge from a large sewage treatment plant (STP) has suppressed growth of diazotrophic cyanobacteria in its inner parts. Implementation of nitrogen removal in the STP in 1997 drastically reduced nitrogen load and triggered growth of diazotrophs, mainly Aphanizomenon sp. LÄS MER

  5. 9. Proteomic profiles and gene expressions in the symbiotically competent cyanobacterium Nostoc sp. PCC 73102

    Författare :Liang Ran; Birgitta Bergman; Karl Forchhammer; Stockholms universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Nostoc PCC 73102; hormogonia; 2-DE; symbiosis; photo-autotrophy; heterotrophy; cell differentiation; Microbiology; Mikrobiologi; mikrobiologi; Microbiology;

    Sammanfattning : Nostoc PCC 73102 is an evolutionary important cyanobacterium with multiple phenotypic traits and symbiotic capacities. Based on two-dimensional gel electrophoresis (2-DE) and MALDI-TOF mass spectrometry, a proteomic approach was developed in order to obtain protein profiles of this symbiotically competent cyanobacterium during three trophic types/life stages: free-living photo-autotrophic and diazotrophic growth conditions, dark heterotrophic conditions and hormogonium formation. LÄS MER

  7. 10. Nitrogen fixation among marine bacterioplankton

    Författare :Kjärstin H. Boström; Lasse Riemann; Åke Hagström; Grieg Steward; Högskolan i Kalmar; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Bacterioplankton; Nitrogen fixation; Bakterioplankton; Kvävefixering; Cyanobakterier; Kvävefixerande bakterier; Microbiology; Mikrobiologi; Mikrobiologi; Microbiology;

    Sammanfattning : While bacterioplankton indisputably control vital biogeochemical paths in the cycling of carbon and nutrients in the world’s oceans, our knowledge about the functional and genetic diversity of bacterioplankton communities is negligible. In this thesis, molecular and more traditional microbiological methods were used to study the specific function of N2-fixation and in a general sense diversity of marine bacterioplankton species. LÄS MER